An understanding of the mechanisms by which lymphoid cells transfer information signals are the major goals of this project. These include the transfer of controlling or modulating signals between lymphocytes and also the biochemical pathways by which signals from outside the cell are transmitted past the cell membrane; from the receptors on the cell surface, passing thru the lipid bilayer, and finally redirecting the internal metabolism of the cell. The first of these studies extends our initial observations with a series of helper factors (LSF) produced by T and thymus cells in response to Pa-2 activation. The second extends our studies on membrane phospholipid methylation in response to Con A stimulation. To facilitate these studies we are also seeking to identify and fractionate subpopulations of lymphoid cells: both the producers of each LSF and the targets of these intracellular signals. This is an extension of our studies of differential lectin binding to cells.